ISO 720:2020 PDF

Scope: This document specifies a) a method for determining the hydrolytic resistance of glass grains at 121 °C. The resistance is measured and expressed by the volume of acid required for titration of the alkali extracted from the unit mass of glass, and can also be expressed by the amount of sodium oxide equivalent to this volume of acid, and b) a classification of glass according to the hydrolytic resistance determined by the method of this document. This document is intended for use on the more resistant types of glass, e.g. borosilicate glass. NOTE 1 For the less resistant glasses, e.g. soda-lime, the method specified in ISO 719 is more suited. NOTE 2 It is emphasized that there is no exact correlation between the classification laid down in this document and that laid down in ISO 719, and it is, therefore, essential to identify which classification is being used.

ISO 720:2020 Referenced Document

ISO 13130 Laboratory glassware - Desiccators
ISO 1773 Laboratory glassware - Narrow-necked boiling flasks
ISO 3696 Water for analytical laboratory use; Specification and test methods
ISO 3819 Laboratory glassware - Beakers
ISO 385 Laboratory glassware - Burettes
ISO 565 Test sieves; metal wire cloth, perforated metal plate and electroformed sheet; nominal sizes of openings
ISO 648 Laboratory glassware - Single-volume pipettes

2020 ISO 720:2020 Glass — Hydrolytic resistance of glass grains at 121 °C — Method of test and classification
1985 ISO 720:1985 Glass; Hydrolytic resistance of glass grains at 121 degrees C; Method of test and classification
1981 ISO 720:1981 Glass — Hydrolytic resistance of glass grains at 121 degrees C — Method of test and classification